1. Field of the Invention
The present invention relates to a power supply system and a vehicle and a management device used in the power supply system, and more particularly to the control of a hybrid vehicle capable of supplying power to an external electrical apparatus.
2. Description of Related Art
Recently, a technology is developed for supplying power, stored in or generated by a vehicle, to an external electrical apparatus or a household with an electric vehicle or a hybrid vehicle as the power supply source.
International Publication No. WO2006/059763 discloses a power supply system in which a plurality of vehicles, capable of generating power using the output of an internal combustion engine, is connected in parallel with an electric load as the power supply source. In the power supply system described in International Publication No. WO2006/059763, the power supply amount of the vehicles is allocated based on the load amount of the electric load and the amount of power that can be supplied from each vehicle calculated from the residual fuel.
When a hybrid vehicle, which has both an accumulator device and an internal combustion engine, is used as a power supply source, one of the following two modes may be selected in some cases. In one mode, the power stored in the accumulator device is supplied with the internal combustion engine stopped (hereinafter also called “charged-power supply mode”); in the other mode, the power generated using the output of the internal combustion engine is supplied (hereinafter also “generated power supply mode”).
In such a vehicle, one of the power supply modes described above is selected in some cases according to the state of charge (hereinafter also called SOC) of the accumulator device. For example, when the SOC is higher than a predetermined value, the charged-power supply mode is selected. When the SOC becomes lower than the predetermined value, the generated-power supply mode is selected in which case the power supply is controlled such that the accumulator device is charged while supplying power to an external electric load.
When a plurality of hybrid vehicles is connected to an electric load in this way, it is necessary to appropriately determine the allocation of the amount of power supplied from the vehicles and the power supply mode of the vehicles. In particular, failure to appropriately select the power supply modes of the vehicles results in many vehicles selecting the generated-power supply mode, sometimes generating noises and vibrations, associated with the operation of the internal combustion engines, and increasing the emission of exhaust gas.